Ordinarily, I would agree that the intention of the law is subjective. But in the case of the OTBD ban, the FIA publicised their intentions for nearly a year in advance, and it was quite obvious that Red Bull were trying to recapture the effects that the FIA wanted banned.

In that case, if the only excuse you have is “but it is within the letter of the rules”, then as far as I am concerned, that is no excuse.